Typing indicator

A typing indicator is a promise, not a message. Everything else in a thread reports something that happened; this one reports something that is about to happen, which is why it belongs in the thread rather than in a status bar, and why it is drawn as a bubble with nothing in it. The reader is being told to wait a moment, in the exact place the waiting will end.

That framing decides the behaviour. A promise has to expire: the dots need a timeout of a few seconds after the last keystroke, or a person who starts a sentence, gets distracted, and closes the tab leaves a thread that claims forever that a reply is coming. It has to survive being kept, too, which is the part demos usually skip: the row the dots occupy should be the row the message lands in, at the same height, so the arrival is a replacement rather than a shove that moves everything above it. And it must be honest about who is composing. One person is “Ada is typing”, two is “Ada and Jo are typing”, more than that is “several people are typing”, and a group chat that lists eleven names has turned a courtesy into noise.

The dots need a text equivalent, because a decorative animation says nothing to a screen reader. The usual shape is a live region announcing “Ada is typing” politely, which means aria-live="polite" or role="status" so it waits for a pause rather than interrupting, plus an accessible label on the indicator itself. Keep the announcement short and let it retire when the dots do: a live region that fires on every keystroke is worse than silence. The animation is decoration on top of that text, so it should also stop moving under a reduced motion preference, where three static dots carry the same meaning.

There is a fair critique, and it is worth holding while you build one. The indicator leaks a state the sender never chose to publish, it invites the reader to sit and watch rather than get on with something else, and in a support queue or a chat with an assistant it can be theatre: dots animating over a request that is queued rather than being composed. Several products now let people turn the signal off, and the pattern that borrowed it for machines has mostly moved on to naming the work (“searching the docs”) because a status that says what is happening beats a status that only says that something is.